I planted 2 water lilies in my 1/2 acre pond in NE PA in June of 2009. They survived the winter and did well this summer until a very hot dry spell which resulted in the formation of a lot of FA on the surface of the pond. It covered about 1/4 of the pond surface. After about 2 weeks we returned to the pond after a rainy period and all of the FA was gone from the surface but the lilies lost all of their leaves and flowers. I thought they died. There now appears to be some new growth of small leaves and on one of the plants a small flower. There was no negative impact to the fish during this time. Any ideas as to what happened?